Older female mouse keep licking younger mouse.

Question
Hello, 2 months ago, I bought a female mouse from the pet store, and then about 3 or 4 weeks ago I purchased another female mouse from the same pet store. At first they fought a bit, but are quite friendly now. For the past couple of day I have heard little noises coming out their cage, and each time it appears that the older mouse is biting or licking the coat of the younger mouse. I was worried that she was hurting her, but I've checked the younger mouse for wounds, and I haven't found any, I'm just not quite sure what the older mouse is doing. Any ideas? Thanks.

Answer
Dear Nadine,

Your mice are being as loving as mice can be.  The older mouse is washing her little friend, and I've always imagined it's a bit like when a mother human brushes her daughter's hair a bit too hard and the daughter squeaks a bit.  Or like holding down a child to wash its face.  

Enjoy your happy mice!

squeaks n giggles,

Natasha